To view the zranger value you need to create a new log block with the range.zrange value in "Settings->Logging configurations" while you are connected to a CF2. Wasn't sure you knew about this. For some logging documentation have look here and here.

Hello this is the screenshot
but still the flowsequence script not working and to be honest that is what I need and not the client I still get the same error every time i launch the script and the crazyflie starting to go in random directions

From the information I have it is hard to tell were the error is. That it flies in random directions can be so many things such as assembly problem, sensor error, firmware etc.
If you remove the flow deck can you fly it manually or does it crash directly? One simple test could be to use the mobile client and just do a short thrust up to see that the CF2 takes off straight up.
Another thing, how does the surface look underneath the CF2. If it is glossy, very dark or not so feature rich the flow sensor might not be able to track correctly.